Field of the Invention
The invention concerns a franking machine which can store a record giving the characteristics of each franking operation carried out by the machine. A record of this kind has many applications including: production of statistics, accounting differentiated by departments within a company, accounting differentiated by postal organizations, etc.
Description of the Prior Art
It is desirable for franking machines to be able to generate statistics for the postal organizations using them. If they know the characteristics of each franking operation they can obtain a better statistical knowledge of the postal traffic generated by the franking machines: for example, the number of mail items sent in particular postal charge bands during given periods of the year.
In some countries there is more than one postal organization. They could use the same franking machines, but the latter would then have to enable separate accounts to be produced for each organization.
Users are usually companies having various departments each of which accounts separately for its postal expenses, but sharing a single franking machine. It is then desirable to be able to produce accounts which differentiate franking operations department by department.
The value added tax could feasibly differ according to the particular mailing service used, for example, or all users could be offered a different discount for different types of service. This is another instance in which it is desirable to be able to produce accounts which differentiate between different types of service.
All these applications require a large number of characteristics on each franking operation, covering a long period of time. The main conventional source of information used by postal organizations is a monthly form with one line per day. At the end of each day the user writes on the form the total amount franked indicated by a non-resettable counter. The user calculates the amount for that day by subtracting the total for the previous day from the new total and writes this on the form.
This information is too succinct for producing detailed accounts or statistics and is insufficiently reliable because many users fail to fill in each line of the form as they should.
Also, conventional franking machines are not capable of supplying this quantity of information. A conventional franking machine has two low capacity memories with battery back-up intended primarily to store the total amounts for the franking operations performed. Each of the memories stores this total amount, for added security.
French patent application No 2 665 003 describes a franking machine which can produce a bar chart showing the numbers of franking operations for nine different predetermined franking amounts. It also totals the number of operations for all the other values. This requires ten counters. Changes to postal charges are a serious problem because it is not possible for the staff of the postal organization to modify all the franking machines on the specific day on which the change comes into effect. French patent application No 2 665 003 proposes a solution which entails predetermining the nine values to be monitored by memorizing the first nine different values used for the first franking operations carried out after a credit reloading operation in the case of a prepayment machine. This is a learning process, as it were.
A drawback of this learning process is that one or more non-standard values may appear along the abscissa axis of the bar chart if the user makes mistakes in selecting the first nine different franking values.
Another way to generate statistics is to memorize the characteristics of each operation, including its date and its value, and to apply statistical processing, to produce a bar chart, for example, only when the information is read out from memory. It is then possible to base each operation on an exact price. French patent application No 2 620 249 describes a franking machine comprising a calendar circuit and a non-volatile memory for storing the content of the non-resettable counter and the date for each day on which the machine is used together with the monthly consumption over a period of two months. The monthly consumption and the date are insufficient information for producing statistics. A more refined knowledge is required of the characteristics of each operation over a longer period. A more refined knowledge of the characteristics of each operation would also be required to produce separate accounts.
European patent application No 172 573 describes a franking machine which has three memories. A volatile first memory includes:
an "up" register holding the total amount for the franking operations; PA1 a "down" register holding a credit value and used to check the accuracy of the value in the up register; and PA1 a register containing a cyclic redundancy check code and error checksums. PA1 a) not to write information into the memory if the monitored characteristics of the current franking operation are not different from those of the immediately preceding franking operation; and PA1 b) to write information into the memory if at least one monitored characteristic of the current franking operation differs from that of the immediately preceding franking operation, the information stored in the memory being representative of said characteristic which has changed between two franking operations and being stored in the memory in the form of fixed length data blocks.
At the time of each franking operation a microprocessor subtracts the value of the franking operation from the content of the down register, adds this same value to the content of the up register, and then writes the new content of the up register, the new content of the down register and possibly other characteristics of the operation such as the total number of mail items franked into fixed locations in the first memory.
It also writes them into a non-volatile second memory at successive locations respective to successive franking operations. This EEPROM type second memory can hold the characteristics of the last 128 franking operations. Once it is filled, the first addresses of this memory are re-used. This memory therefore holds a record concerning only the most recent franking operations, the number of these operations being too low for producing statistics because for meaningful results to be obtained it is necessary to know the characteristics of each franking operation over a long period, as much as one year, for example. Also, this memory does not store the date.
A non-volatile CMOS third memory stores at fixed locations the cumulative values contained in the up register, the down register and a number of mail items register (if any) during a power outage in order to back-up this cumulative information which is essential for billing the franking operations. As only the cumulative values are backed up there is no way that statistics can be established from these values.
With the aim of being able to produce statistics it is feasible to modify a franking machine like that described in European patent application No 0 172 573 by increasing the number of franking operations processed and by increasing the number of characteristics stored for each franking operation. The necessity then arises of using a record memory having a very large capacity to enable production of statistics over a long period. This very large capacity would significantly increase the cost of the machine.
A known way to establish a separate account for each postal organization or for each department within a company is to store a plurality of up counters and a plurality of down counters, rather than only one, in a non-volatile memory with a back up memory. This solution is not very satisfactory, however: either it requires a memory capacity that would be of no utility to most users, or it restricts the number of counters to a value that is too low for some users.
An object of the invention is to propose a franking machine which can generate statistics and produce separate accounts for different departments within a company or for different postal organizations without any notable increase in the cost of the machine.